Question

Lets say i have these 3 classes

class Human
  public void eat()

class Lawyer extends Human
  public void beEvil()

class Murderer extends Human
  public void beEvil()
  public void kill()

Now i have a handler for actions, and i want to handle actions without knowing what i am. So for example:

handleBeEvil(Human human)
{
    ..
    human.beEvil(); //wont obviously work
    ..
}

In as3 for example, i woud use

handleBeEvil(Object human)
{
   human.beEvil(); //would pass compiler, work or break runtime
}

Whats the best way to accomplish this in Java? I would like to avoid putting all the declerations in the Human class.

Answer 1

Create an interface and have both Lawyer and Murderer implement it (i.e. class Lawyer extends Human implements Evil):

interface Evil {
    void beEvil();
}

Then your method would be

... handleBeEvil(Evil human)
{
    ..
    human.beEvil();  // now this will work
    ..
}